Conventionally, there have been known a ventricular assist blood pump which includes: a rotational part having an impeller; and housing which houses the rotational part therein (see patent literature 1 and non-patent literature 1, for example).
FIG. 6 is an exploded perspective view of a conventional ventricular assist blood pump 900. As shown in FIG. 6, the ventricular assist blood pump 900 includes: a rotational part 910 having an impeller 912; and housings 920, 922 which house the rotational part 910 therein. Such a conventional ventricular assist blood pump 900 can assist an action of a heart of a patient having cardiopathy during a period till he receives a heart transplant.